Reaching onto his rival’s political turf, Rep. Charles Rangel has gained the support of Dominican political trailblazer Guillermo Linares in his bid for a 22nd term, The Post has learned.

Linares’ endorsement of Rangel — expected as early as Friday — is a shot across the bow of a Dem challenger, state Sen. Adriano Espaillat, source said.

Both Espaillat and Linares, the state assemblyman who is now running for Espaillat’s state Senate seat, hail from Washington Heights.

Linares was the first Dominican-born candidate elected to a political post in the Uuited States when he won a City Council seat in 1991. He also served as Mayor Bloomberg’s commissioner of immigrant affairs.

“We’re going into Adriano’s base,” crowed a Rangel insider.

Linares declined to comment last night, other than to say he will announce his decision shortly.

Rangel also won the endorsement of his chief rival from two years ago, Adam Clayton Powell IV, the son of Rangel’s predecessor in Congress, Adam Clayton Powell Jr. They will appear at a press conference today.